The present invention relates to a mouthpiece for inhalation therapy units comprising the features of the preamble of patent claim 1.
Such a mouthpiece is known from the utility model G 93 21 308.5, which is fitted onto an outlet connecting member of the inhalation therapy unit for inhalation of a drug-containing aerosol produced in an inhalation therapy unit. The known mouthpiece comprises a check valve, which closes an orifice formed in the wall of the mouthpiece during the inhalation process, so that during the inhalation process the patient inhales the aerosol produced by the therapy unit. During exhalation, the valve member opens the orifice so that the respiratory air is removed directly from the mouthpiece and does not enter the therapy unit in a considerable amount. The known mouthpiece is constructed in such a manner that the orifice is provided in a substantially flat wall portion of the mouthpiece. The check valve is formed as a flat, elastic valve member, the dimensions and shape of which are adapted to the orifice for the closing thereof. The valve member is secured externally on the base in the region of the flat wall portion by means of a clamping device in such a manner that in its home position it abuts against the base on account of the effective elastic forces and closes the orifice. For the opening of the orifice the valve member can be raised partially from the base by means of the respiratory air flow.
In the known mouthpiece it has become evident that aerosol droplets accumulate in the region of the orifice or on the elastic valve element itself. This accumulation of liquid is so strong that the accumulated droplets spatter into the environment when the orifice is opened, i.e. when the valve member is raised during the expiration process. In this manner aerosol droplets can spatter into the face or eyes of the patient
It is therefore the object of the invention to improve the known mouthpiece for inhalation therapy units in such a manner that the spattering of liquid is avoided when the orifice formed in the base of the mouthpiece is opened by the valve member
The object is solved by a mouthpiece for inhalation therapy units which an aerosol for inhalation is produced for a patient to inhale, said mouthpiece having a substantially tubular base in the wall of which an orifice is formed, and a flat, elastic valve member adapted in dimension and shape to the orifice for the closing thereof, and which is secured to the mouthpiece in such a manner that during an inhalation process through the mouthpiece the orifice is closed and during an exhalation process directed into the mouthpiece the orifice is opened, wherein at least one enlarged contact surface is provided at the orifice for the accumulation and holding of an amount of liquid by adhesion
It is advantageous for the enlarged contact surface to be provided especially on the side of the orifice lying opposite the securement position of the valve member.
According to the invention, the enlarged contact surface can be created in that a collar is formed on the margin of the orifice, the edge of which forms an abutment surface for the valve member.
Furthermore, the enlarged contact surface can be created in that a bar extending into the opening of the mouthpiece is provided. Advantageously the bar extends in the longitudinal direction of the base. The bar also prevents the valve member from being suctioned into the mouthpiece.
In a further configuration, the bar extends under the plane of the orifice into the base. In this manner, the size of the surface, namely the side surface of the bar which is prepared as the enlarged contact surface, is increased.
In order to also partially include the inside wall of the mouthpiece as the enlarged contact surface according to the invention, it is advantagous to provide an extension bar that joins onto the bar arranged in the orifice and extends on the inside wall of the base.
Especially for the purpose of the return of the liquid, a cross-bar is provided that joins onto the bar or extension bar arranged in the orifice and extends transversely across the base.
In a further configuration, a securement aperture is provided in the base for securing the valve member in the proximity of the orifice, which can be for example a slot. As a counterpart, the flat, elastic valve member comprises a securement protrusion that can be inserted into the securement aperture to secure the valve member.
In an especially advantageous configuration, a wedge-shaped protrusion is provided on the outer wall of the base so that the valve member can be secured onto the mouthpiece essentially free of initial stress. In this respect it is advantageous for the securement aperture to be arranged in the wedge-shaped protrusion.
In summary, the invention describes a mouthpiece for an inhalation therapy unit in which an aerosol for inhalation is produced to inhale for a patient, said mouthpiece comprising a substantially tubular base, in the wall of which an orifice is formed, and a flat, elastic valve member which is adapted in dimension and shape to the orifice for the closing thereof, and which is secured to the mouthpiece in such a manner that during an inhalation process through the mouthpiece the orifice is closed and during an exhalation process directed into the mouthpiece the orifice is opened. According to the invention, at least one enlarged contact surface is provided at the orifice for the accumulation and holding of an amount of liquid by adhesion. This contact surface is established both by an outwardly directed collar surrounding the orifice and by a narrow bar that extends into the orifice in the longitudinal direction of the mouthpiece or transverse to the mouthpiece.